Java 256-bit AES Password-Based Encryption

Question

I need to implement 256 bit AES encryption, but all the examples I have found online use a \"KeyGenerator\" to generate a 256 bit key, but I would like to use my own passkey

Answer 1

Use this class for encryption. It works.

public class ObjectCrypter {


    public static byte[] encrypt(byte[] ivBytes, byte[] keyBytes, byte[] mes) 
            throws NoSuchAlgorithmException,
            NoSuchPaddingException,
            InvalidKeyException,
            InvalidAlgorithmParameterException,
            IllegalBlockSizeException,
            BadPaddingException, IOException {

        AlgorithmParameterSpec ivSpec = new IvParameterSpec(ivBytes);
        SecretKeySpec newKey = new SecretKeySpec(keyBytes, "AES");
        Cipher cipher = null;
        cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        cipher.init(Cipher.ENCRYPT_MODE, newKey, ivSpec);
        return  cipher.doFinal(mes);

    }

    public static byte[] decrypt(byte[] ivBytes, byte[] keyBytes, byte[] bytes) 
            throws NoSuchAlgorithmException,
            NoSuchPaddingException,
            InvalidKeyException,
            InvalidAlgorithmParameterException,
            IllegalBlockSizeException,
            BadPaddingException, IOException, ClassNotFoundException {

        AlgorithmParameterSpec ivSpec = new IvParameterSpec(ivBytes);
        SecretKeySpec newKey = new SecretKeySpec(keyBytes, "AES");
        Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        cipher.init(Cipher.DECRYPT_MODE, newKey, ivSpec);
        return  cipher.doFinal(bytes);

    }
}

And these are ivBytes and a random key;

String key = "e8ffc7e56311679f12b6fc91aa77a5eb";

byte[] ivBytes = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
keyBytes = key.getBytes("UTF-8");